(19)

(11)

EP 2 304 178 A1

(12)

(43) Date of publication: 06.04.2011 Bulletin 2011/14 (21) Application number: 09742925.2 (22) Date of filing: 11.05.2009

(51) International Patent Classification (IPC):  E21D 20/00(2006.01) E21B 7/02(2006.01) E21B 15/00(2006.01) (86) International application number: PCT/SE2009/000242 (87) International publication number: WO 2009/136843 (12.11.2009 Gazette 2009/46)

(84) Designated Contracting States: AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO SE SI SK TR Designated Extension States: AL BA RS (30) Priority: 09.05.2008 SE 0801050 (71) Applicant: Atlas Copco Rock Drills AB 701 91 Örebro (SE)	(72) Inventor: NYSTRÖM. Sven-Olov S-702 26 Örebro (SE)